Internal-combustion engine



C.' A. HUH'.` INTERNAL CUMBUSTIOM ENGINE.

man Auen, wao. a MEETS-SWEET n.

Feb, 24U?, 1923, K 'lLM c. A. HuLT:vl

INTERNAL COMBUSTIONENGINE.

FILED AUG 71| l9.2v0.` 3 SHEETS-SHEET 3.

` WW Mw l M w V w To all/whom tnwy concern:

iraniana ttt.. au, lara v'MTE UML ALBIR JEUULT, 0F STUJMHLM, SWEDEN.

rn'rnnnarrconnusrroiv nivornn.

Be it known that l, CARL Amun HULT, a subject of the Kin of Sweden, residin at 'lorsgatanv 4, Stoc iolm, in the King om of Sweden, have invented certain new andy useful Improvements 'in Internal-Combustion Engines, of which the following is a specification. n 'lhis invention relates to reciprocating internal combustion engines. i

An internal combustion engine, construct-N ed according to this invention, has anannular cylinder with two pistons, working to and from each other and co-o-perating with cam tracks, fixed to an engine shaft in order to e'dect a relative rotary movement 'between the cylinder and the said shaft, said shaft being mounted axially with regard to the cylinder. Acommon 'explosion or conibustion space is provided. For the admission of the gas mixture and the exhaust of the combustion gases the annular space between the linner wall of the annular cylinder and the engine shaft is used. By an opening in the inner wall of the cylinder this annul-ar space communicates with the common combustion space. On that account the device for the admission and the exhaust `ot the gases can be made very simple and effective, the regulation being made by means of simple valves or -a slide valve `provided in the said room and actuated by cam discs on the engine shaft. The cam tracks ,till

`first mentioned are so arranged' that the effect of the engine will be the greatest possible. According to the invention the cam tracks further` may be so' arranged that two impulses 0f power are' gained at each revo# ]ution of the engine shaft, thus as many as in a four-cycle engine with four cylinders.

The above mentioned and other arrange 4ments are more particularly described in the following description, reference being had to the accompanying drawings.

ln these drawings, 4as an example, a combustion engine constructed' according to the invention is shown.`

Figure 1 is alongitudinal section of the engine..

Figure 2 is a transverse section of the engine along the line 2-2 in Figure 1.

Figure 3 is an outside view of the engine on a reduced scale.- Figure 4 is a longitudinal section of the central part of the engine replication med. august 7,' wao. serial no. toneel.

and shows on a larger scale the valve device of the engine. y

Figure 5 is a longitudinal section of the central part of the engine but with a slide valve substituted for the valve device show in Figure 5.

F'gure 6 shows the half of one of the two cam tracks ofkthe engine evolved.

In the engine shown in the drawings, the frame 1 constitutes the outer cylindrical wall of the working-cylinder. The innen cylin drical wall consists of a cylinder 2which is fastened to the cylinder covers 8which in turn are fixed-to the outer cylinder. ln the worklng cylinder thus formed, Itwo annular pistons 4 and 5 operate, each of them being` provided with two pistons rods 6 and 7, 8 and 9 respectively fixed to the pistons, diametrical to each other.

To the outer end of the piston rods 6 and 7 a cnos's beam 10 is fastened, and to the outer end of the piston rods 8 and 9 a similar cross beam 11 is fastened. 0n the cross beams 10 and 11 rollers l13 are provided, journalled by means of roller or ball bearings 12.l The rollers 13 co-operate with cam tracks 14 and 15 respectively,` fastened to discs 16 and 17, which are mounted upon the engine shaft 18. 'lhe engine shaft 18 extends through the engine co-axial to.

beams 10 and 11 co-operate. At the opposite side of the engine there is a cylindrical casing 24, containing two plungers' 25 and 26 fastened to the cross beams 1() and.11 respectively. the whole constituting a pneumatic buffer for the same, for the purpose hereinafter described.

In the wall of the inner cylinder.2 a transverse central inlet 27 is provided, Figures l and 4, which extends around the whole circumference of the cylinder except where short stays- 28, Figure 2, formed by the cylinder wall connect both parts of the cylinder 2. Within the cylinder 2 there is a coaxial sleeve shaped valve body 29, sliding axially and provided with a flange 30, situated at the inlet 27 concentric to the cylinder 2 and directed outwardly towards same. The said flange 30 is provided with conical surfaces 31 and 32, by means of which the flange 30 seats against the sliding .sleeves 33 and 34. These are guided by the'cylinder 2 and constitute a guide for 'the sleeve shaped valve 29.

Between 'the sleeves 29 and 33l there is a passage 35, which by the opening 36 in the sleeve 33 communicates with a passage 37 formed in the cylinder 2, which passage communicates with a space 38 in the left cylinder` cover 3, to which space or recess an inlet channel 39 Figure 3 for the gas mixture is connected.

Between the sleeves 29 and 34 ia passage 40 is. provided, which by openings 41 in the sleeve 34, a passage 42 in the wall of the cylinder 2 and a space or recess 43 in the other cylinder cover 3 communicates with an outlet 44, Figure 3, for the combustion gases.l The sleeves 33 and 34 together with the iiange. 3() on the sleeve 29 constitute valves for the admission of the gas mixture linto the working cylinder and the exhaust of the combustion gases respectively.

The left end of the sleeve 29 .is provided with a suitable projection 45, Figure 4, which, when the suction of tlie gas mixture is to take place, 4is actuated by a roller 46 /or cam/on a collar 47, iixed to the engine shaft 18.` The sleeve 29 on its right end has a similar projection 48, which, when the exhaustl of the combustion gases is to take place, as actuated by a roller 49 /or cam/ on a collar 50, fastened to the engine shaft 18.

A spring 51 bears with one of its ends against the cover 3 of the cylinder and with the other end against the sleeve 33. A similar spring 52 is provided between the sleeve 34 and the other cover 3 of the cylinder.

'The outer cylinder 1 and the inner cylinder 2 are provided with water jacketsA 53 and 54 respectively. j

`The pistons 4 and 5 are on the Aouter circumference provided Awith piston rings 55 and inthe wall of the cylinder 2 rings 56 are provided seating against the inner side of the pistons.

The engine as above described, which is a four cycle engine, works in the following manner. When at the start the pistons are moved `from each other, the gas mixture is sucked into the cylinder space between same. At the beginning of the suction stroke the roller 46 actuating the projection 45, forces the sleeve 29 toward the right, so that the flange 30 is moved from the sleeve 33 yand the gas mixture passes through the space 38, the passages 37 and 35 and the inlet opening 27 into the cylinder. During the said move- -ment of the sleeve 29 the sleeve 33 is kept in its position by a flange 57 vbearing against 1 ange 58 on the inner cylinder The y sleeve 34 on the other hand is moved toward the right against the action of the spring 52. When the roller 46 has passed the projection 45 at the left end of the sleeve 29, the spring 52 forces the sleeve 34 and the sleeve 29 toward the left, so that the sleeve 30 again bears against the sleeve 33 and the iniiow of the gas mixture is cut ofi".

During the inward motion of the pistons the gas mixture is compressed, and when the compression has taken place, the gas mixture is iired by means of an electrical ignition device,`(not shown), or otherwise. During the next outward stroke of the pistons the expansion takes place. At the end of the saine the roller 49 on the collar 50 actuates the valve sleeve 29 and forces the' saine toward the left from the sleeve 34, so that the space between the pistons by the opening 27, the passages 40 and 42 and the space 43 is brought in communication with the outlet 44, and the combustion gases are driven out during the next inwardstroke of the pistons. The sleeve 34 is kept in its position by a lange 59 resting against a flange 58 on the right end of the inner cylinder 2.

Owing to the fact that the opening 27 extends substantially around the whole cir cumference of the cylinder 2 and in consequence of the spacious channels 35 and 4() the gasmixture can be sucked into the cylinder and the combustion gases be driven out at a low speed for which reason any essential reduction of the admission pressure or increase of the counter pressure at exhaust of the combustion gases does not occur, which is advantageous to the eiiiciency of the engine. As seen from the drawings the valve device is very simple and requires a small space, and further the length of the valve strokes can be very short. Moreover it may be pointed out that the clearance including the passage communicating with the same is reduced to a minimum.

The cam tracks 14 and 15, carried by the engine shaft 18, are arranged in the same inannerwherefore only one of them is shown in Figure 6. This figure only shows one hall of the cam track evolved. The second half is arranged in quite the same way as that shown. Each cam track has two series of curves, each of the series comprising one curve for the period of'suction, one curve for the period of compression, one curve for the period of expansion and one curve for the period of exhaust, so that the engine receives two impulses at each revolution.

In consequence of this, the impulses are quadrupled, compared to a common four cycle cylinder engine and the advantage is gained, that the iiyzwheel or the fly wheels can bemade very light and the engine can be so arranged that it requires a small space` which cheapcns the cost of its manufacture. The cam curves in'Figure 6 are designated naaaeee forced against the curves 60, whereby a lateral pressure arises, which tends to turn the pistons round their axis. This however, 1s prevented by the rollers running'inthe stationary `guides 21, which thus will susder arises with loss of tain the said lateral pressure, and the pressure of the pistons will turn the cam discs 14 and 15, and thereby the engine shaft 18. By this arrangement no counterpressure between the pistons and the walls of the cylinpower by friction, as is the case with engines where the power is transmitted from the piston tothe engine shaft by means of a crank and a connecting rod. By means of the torce, which during the stroke of expansion is accumulated in the cam discs, which are made suiiiciently large for such an accumulation, the cam discs and the engine shaft continue rotating during the next operations, viz, exhaust, suction and compression. l i

During the expansion the rollers run down to the deepest points of theV curves 60 respectively, which are the deepest points of the cam tracks respectively. The pistons are then driven inward by the curves 61, the

rollers 13 running upto the highest point' of the cam discs 14 and 15 forcingthe pistons close up to each other, so that the combustion gases as completely as possible are' vdriven out of the cylinder. At the inward motion of the pistons the sprin 23 and the plungers 25 and 26 resist the riving force of the reciprocating parts. During the continued rotation of the engine shaft 18v and the cam discs 14 and 15 the outwards from each other y the torce, accumulated in the spring 23 'and the pneumatic buffer, the rollers running along the cam tracks 62. Meanwhile a new charge of gases is sucked into the cylinder, which charge during the continued runningof the rollers 13 along the cam -tracks 63 is coinpressed, whereupon the ignition takes place and the cycle, above described, is repeated.

r1`he cam curves 60, 61, 62 and 63 have different heights and lengths as is best shown in Figure 6. The curve 62 for the suction of the charge ,of gas is preferably so low, that only such'a quantity-oi` gasesis sucked into the cylinder as can, after compression by the operation of the' curve 63, becompletely or almost completely expanded to the f atmospheric pressure at the'end of the pis- Iton stroke. Because the combustion gases are' almost completely driven out-.of the cylindcr and the nextcharge migas consequentistons are forced` vnormal 'positian ,by the spring 70.

ly is as pure as possible and further because no greater charge oi gases is sucked into the cylinder than can be expanded down towards the atmospheric pressure, the efficipcy of the engine will be the greatest poss1 e.

rlhe application of the invention, shown' in Figure 5, did'ers from the one described above only thereby, that a sleeve-shaped slide'valve 64 with double walls is substituted for the sleeves 29, 33 and 34. The slide valve 64 is provided with a central partition 65 which, in the position of the slide valve shown in Figure '5, covers the opening 27 of the inner cylinder 2. Un both sides of the partition 65 openings 66 and 67 are provided communicating with the spaces between the walls of the slide valve, and at one ings 68, through which the left chamber of the slide valve communicates with the passage 37, the space 38" and the inlet for the gas mixture. Corresponding side openings 69 atthe other end of the slide valve keep the right chamber 'of the same in communication with the passage 42, the space 43 and the outlet for the combustion gases. The ends of the slide valve 64 are actuated by springs 70 and 71'.

The rollers 46 and 49, carried byr the engine shaft 18, actuate projections or cams 72 and 73 respectively on the ends of the slide valve 64, which cams are so situated, that the roller 46 during the rotation of the engine shaft 18 at the right moment forces the slide valve 64 toward the right against the pressure of the spring 71, the opening 66 thus coming in register with the opening 27 and the gas mixture being sucked into the cylinder. rllhe slide valve is then returned to its closing position by the spring 71. During4 the exhaust stroke the slide valve is `forced toward the left by the roller 49, actuating the cam 73, so that the openings 67 come into register with the opening 27, whereupon the slide valve is returned to its A key 74, fixed to the cylinder and engaging a keyway 75 of the slide valve 64, prevents the latter from rotating. l

In the described examples of the applicatio-n of the invention the forces of inertia of the pistons are balanced by the simultaneous working of the pistons to and from each other inv-a common cylinder. By this the pressures on the pistons and consequently also on the cam discs become equal, and the axial pressure on the engine shaft and the discs is completely balanced and neutralized.

While the curves ot the cam tracks are so though the curves for the dierent operations, compared with one another, .may be of a quite unequal shape, as above mentioned and shown in Figure 6, the impulses of power, transmitted by the two rollers 13 of lthe pair of rollers, are also equally divided and balanced on each side of the enofine shaft, and consequently no one-sided raIlia-l pressure on the engine shaft arises.`

I claim ll. .In an internal combustion engine the comblnatlon with an annularcylmder and two 'annular plstons working therein, of a slngle combustion chamber between the said pistons and common to the same, in which chamber thesaid pistons move from and approach close to each other, controlling means provided at the inner annular wall of the cylinder and means for shifting the same, the

Y said controlling means effecting a narrow assaoe at the inner wall extendiner round the same and serving as outlet for the com-l buston gases and preferably alsoV as inlet for the fuel charge.

2. In an internal combustion engine the combination with an annular cylinder and two annular pistons working therein, of a single combustion chamber between the said pistons and common to the same, in which chamber the said pistons move from and apl preach close'to each other, a central slot pro! vided in the inner annular wall of cylinder and extending round the same, an admis- ,sion passage for the fuel and an exhaust pasmoment between the cylinder and the cam tracks, of a single combustion chamber between the said pistons and common to the A- same, in which chamber the said pistons move from and` approach to each other, controlling means provided at the inner annular wall ofvthecylinder and means for shifting the same, the said controlling means effecting a passage at the inner wall' extending round the same and serving as outlet for the combuston gases and preferably also as inlet for the fuel charge, and the cam tracks being so arranged, that the expansion and exhaust strokes of the .pistons are greater than the suction and the compression strokes of the same.

of the shaft, inlet and outlet for the fuel and the combustion gases respectively located in ,the inner wall of the cylinder, two sliding Sleeves guided by the inner wall of the c vlinder, one at each side o-f the said inlet and outlet, the inner ends of the sleeves being shaped 'as valve seats, a. sleeve-shaped valve body, located inside the said sliding sleeves and provided with a fia-nge, co-operating with the said seats, an annular room between the sliding sleeve and the valve body and communicating with the admission passage for the fuel and the discharge opening for the combustion gases, yielding` meansforcing the said sliding sleeves against the said flange, abutments for the said sliding sleeves, and means provided xon the said shaft and actuating the said val,ve body, so that, when moved in one direction or another, it carries with it one of the sleeves but is removed from the other sleeve and the cylinder is set in communica-tion with the said annular room.

-5. In an internal combustion engine the combination of an annularfcylinder, formed by one outer and one inner ,cylindei, the latter being kept in position by covers fastened to the ends of the cylinders, two annular )istons working in the said annular cylin( er, a combustion space between the said pistons and common to the same, a rotary shaft, cam tracks provided on the said shaft and co-operating with the said pistons in order to effect rotary movement of the shaft'` inlet and outlet for the fuel and the combustion gases respectively located in the said inner cylinder, chambers which are provided in the said covers and to which neceary connections are joined, passages communicating 'with the said chambers, means controlling the communication between the said inlet and outlet and the said passages-iespectively, and means provided on the said shaft and actuating the said controlling means.

In testimony whereof I have ailixed my sngnature vin presence of two witnesses.

. CARL ALRIK HULT. Witnesses:

ROBERT ArnLGnnN, ICLIN WAHMAN. 

